Method for manufacturing transfer paper

ABSTRACT

A method of making transfer paper in which surfactant is applied either after the step of refining and before the paper sheet formed or on the surface of the paper sheet. The surfactant includes aqueous wax emulsion or fluorochemical. The present disclosure accomplishes papermaking by paper machine, with no need of coater.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Chinese patentapplication No. 201510404084.X, titled “METHOD FOR MANUFACTURINGTRANSFER PAPER”, filed with the Chinese State Intellectual PropertyOffice on Jul. 10, 2015.

BACKGROUND

Technical Field

The present disclosure relates to the manufacture of low-surface-tensiontransfer paper, which belongs to the technical field of papermaking.

Description of Related Art

Making ink jet transfer printing paper includes the produce of basepaperby paper machine and a layer on the surface of the basepaper by coater.The coating layer allows inks or paints to remain on the surface of thebasepaper, resulting in high transferring rate. FIG. 1 schematicallydepicts the procedure to obtain basepaper by the paper machine. Theprocedure sequentially comprises following steps: pulp preparation,dissolution, refining, filtering, blend, dilution, pump, forming papersheet, press, pre-drying, surface sizing, and after-drying. In details,pulp preparation preliminarily makes pulp from wood, cotton, line orother sources and then presses the pulp into a board to ease transfer.Dissolution refers to the mixing of recycled water, often called whitewater, with the pulp board. By refining, the dissolute pulp ismechanically grinded to get strengthened. Filtering removes insolublemasses from the pulp. Blend mixes various pulps at mixing chest.Dilution adjusts the concentration of the pulp mixture by adding whitewater. Then the pulp mixture is pumped to a moving former, at which somewater is drained. Paper sheet is formed at this point and getstransferred to press section of the paper machine to further removewater. After that, the paper sheet is steamed for pre-drying. Starch orother sizing agents are exerted on the surface of the dried paper sheet.Finally the paper sheet is steamed again for after-drying. Basepaper,the final product of the paper machine, is then carried to a coater toget coated and dried. The coating layer should cover the surface of thebasepaper as much as possible to prevent the penetration of inks orpaints to the interface of the basepaper. The coating weight of coatingcolor should be no less than 4 g/m² to completely cover the papersurface. However, the materials of coating color are comprised ofH₂O-absorbing chemicals, such as Carboxymethyl cellulose. Transfer papercoated with these substances absorbs H₂O and gets curling at humidcircumstance. In addition, the conventional art needs coater besides thepaper machine, which complicates the paper making process.

Coating basepaper at the step of surface sizing by the paper machine iscapable to simplify the process by eliminating the coater. However, thethickness of the coating layer is restricted due to the paper machine.Therefore, the coating layer cannot completely prevent ink or paintsfrom penetrating into the interface of paper. Transfer paper producedwith this method is low at transferring rate and unqualified forhigh-resolution transfer printing.

SUMMARY

The present disclosure provides a method for manufacturing transferpaper including the operation of adding surfactant. The surfactant iseither added into the pulp at wet end of the paper machine or coated onthe surface of the basepaper during the surface sizing. The presentdisclosure finishes papermaking in the paper machine and coater is notnecessary in this process.

The foregoing has outlined rather broadly the features and technicaladvantages of the present disclosure in order that the detaileddescription that follows may be better understood.

BRIEF DESCRIPTION OF THE DRAWINGS

The components in the drawing are not necessarily drawn to scale, theemphasis instead being placed upon clearly illustrating the principlesof the described embodiments. In the drawings, reference numeralsdesignate corresponding parts throughout various views, and all theviews are schematic.

FIG. 1 is a flow chart of a conventional method for papermaking by papermachine;

FIG. 2 is flow chart showing a method for manufacturing transfer paperin accordance with an embodiment of the present disclosure.

FIG. 3 is flow chart showing a method for manufacturing transfer paperin accordance with another embodiment of the present disclosure.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Reference will now be made to the drawing figures to describe exampleembodiments of the present disclosure in detail. In the followingdescription, the same drawing reference numerals are used for the sameelements in different drawings.

The present disclosure refers to the method of manufacturing transferpaper with additive agent to decrease the surface tension. The additiveagent which is added to the interior or exterior of the transfer paperallows the inks and paints to remain on the surface of the paper.

In an embodiment, the additive agent is added at the wet end of thepaper machine Thereby, the agent is mixed to the interior of transferpaper. In another embodiment, the additive agent is added during surfacesizing when the paper sheet is formed. Thereby, the agent is coated onthe surface of the transfer paper.

FIG. 2 schematically depicts that the additive agent is applied at thewet end of the paper machine, more particularly, after the step ofrefining and before the paper sheet is formed (illustrated by the dashedline box 10).

The additive agent is surfactant that includes but not limited toaqueous wax emulsion or fluorochemical. The surfactant is appliedindividually or with a combination of two or more types of surfactants.

The aqueous wax emulsion may be paraffin wax emulsion or water-basedpolyethylene wax. The fluorochemical may be C3 or C6 or C8 (3/6/8 carbonatoms) organic fluorine oil repellent or fluorine silicide.

In an embodiment, 1-30 kilograms of the surfactant is applied to a tonof basepaper.

FIG. 3 schematically depicts that the surfactant is added during surfacesizing at the dry end of paper machine (illustrated by the dashed linebox 20). Surfactant is applied individually or with a combination ofsizing agents to the surface of formed paper sheet. The sizing agentsinclude but not limited to starch, carboxymethyl cellulose and polyvinylalcohol. If applied with sizing agent, in an embodiment the weight ratioof surfactant to sizing agents is from 1:0.5 to 1:20. In an embodiment,the weight ratio of surfactant to sizing agents is from 1:5 to 1:10.

The present disclosure is based on the capillary reaction occurredbetween inks and the surface of paper during printing process. Thepresent disclosure reduces the surface tension of the transfer paper toresist the penetration of inks. Paper obtained in this method improvesresolution and transferring rate in printing.

Six embodiments will be given hereinafter.

First Embodiment

A bleaching chemical pulp mixture is utilized to make paper. The pulpmixture, for example, includes 30 percent by weight of soft wood pulpwith 400±20 ml Canadian Standard Freeness (CSF) and 70 percent by weightof hardwood pulp with 420±20 ml CSF.

Other pulp articles are also applicable for the pulp mixture.

The softwood pulp and hardwood pulp are digested, refined, as well asfiltered respectively, and then flow into mixing chest to get combined.At the outlet of the mixing chest, fluorochemical is added in the amountof 30 kilogram per ton of the basepaper.

The fluorochemical is also capable to be applied at sites between theoutlet of the refiner and the inlet of the fan pump. Pumping isperformed by the fan pump. More specifically, the sites are either atthe mixing chest, or at the over headbox which is located between themixing chest and the fan pump, or at the inlet of the fan pump. At thesesites, it is easy to control the adding amount of additive agent.

After added with regular chemicals, the pulp mixture flows away from thehead box onto a moving former of the paper machine to form paper sheet.The formed paper sheet leaves from the wet end of the paper machine to apress section and sequentially to the dry end of the paper machine to befurther treated.

At the dry end of the paper machine, the pre-dried paper sheet isapplied with tapioca starch in an amount of 3 g/m² on the surface forsizing. The sized paper is then after-dried and wound on a reel to getfinal product. In this process, the tapioca starch can be replaced byother sizing agents.

This embodiment reduces the amount of sizing agent to less than 4 g/m²and still can prevent inks to penetrate into the interface of transferpaper. All these above processes are finished in paper machine. Transferpaper produced in this embodiment is smooth and not easy to get curled.The paper is qualified for high-resolution transferring print, and thetransferring rate reaches 90%.

Second Embodiment

Pulp mixture is prepared in a similar manner as the first embodiment.

The soft wood pulp and the hardwood pulp are digested, refined, as wellas filtered respectively, and then pumped into the mixing chest to getcombined. After added with regular chemicals, the pulp mixture flowsaway from the head box onto the moving former of the paper machine toform paper sheet. The formed paper sheet leaves from the wet end of thepaper machine to the press section and afterwards moves to the dry endof the paper machine to be further treated.

At the surface sizing section, C3 or C6 or C8 (3/6/8 carbon atoms)organic fluorine oil repellent or fluorine silicide is applied on thecoating surface of the pre-dried paper sheet in an amount of 20 kilogramper ton of paper.

The paper sheet is then coated with regular sizing agents. After that,the paper sheet is post-dried and wound on a reel to get final product.

Transfer paper produced in this embodiment reaches transferring rate of95%.

Third Embodiment

Pulp mixture is prepared in the same manner as that in the firstembodiment.

The soft wood pulp and the hardwood pulp are digested, refined, as wellas filtered respectively, and then flow into the mixing chest to getcombined. After added with regular chemicals, the pulp mixture flowsaway from the head box onto the moving former of the paper machine toform paper sheet. The formed paper sheet leaves from the wet end of thepaper machine to the press section and afterwards moves to the dry endof the paper machine to be further treated.

At the dry end of the paper machine, fluorochemical is applied togetherwith regular sizing agents on surface of the pre-dried paper sheet in anamount of 6 kilogram per ton of paper. In the mixture of the sizingagents, the weight ratio of fluorochemical to starch is 1:10. And themixture is applied in an amount of 3 g/m² on the surface of paper sheet.After that, the paper is post-dried and wound on a reel to get finalproduct.

Transfer paper produced in this embodiment reaches a transferring rateof 88%.

Forth Embodiment

Paper sheet is obtained in a similar manner as the third embodiment.

At the dry end of the paper machine, fluorochemical is applied togetherwith regular sizing agents on the surface of the pre-dried paper sheetduring sizing procedure. The difference between this embodiment and thethird one is that the fluorochemical is added in an amount of 1 kilogramper ton of paper. In the mixture of the sizing agents, the weight ratioof fluorochemical to starch is 1:10. And the mixture is coated in anamount of 3 g/m² on surface of the paper sheet. After that, the paper ispost-dried and wound on a reel to get final product.

Fifth Embodiment

Pulp mixture is prepared in a similar manner as the first embodiment.

The soft wood pulp and the hardwood pulp are digested, refined, andfiltered respectively, and then flow into the mixing chest to getcombined. After added with regular chemicals, the pulp mixture flowsaway from the head box onto the moving former of the paper machine toform paper sheet. The formed paper sheet leaves from the wet end of thepaper machine to the press section and afterwards moves to the dry endof the paper machine to be further treated.

At the dry end of the paper machine, water-based polyethylene wax isapplied with a mixture of regular sizing agents to the coating surfaceof the pre-dried paper sheet. The water-based polyethylene wax is addedin an amount of 20 kilogram per ton of paper. In the mixture of thesizing agents, the weight ratio of water-based polyethylene wax tostarch is 1:5. And the mixture is coated with the amount of 3 g/m² onthe surface of paper sheet. After that, the paper is post-dried andwound on a reel to get final product.

Transfer paper produced in this embodiment reaches transferring rate of88%.

Sixth Embodiment

Paper sheet is obtained in a similar manner as the fifth embodiment.

In the embodiment, water-based polyethylene wax is applied with amixture of regular sizing agents to the coating surface of the pre-driedpaper sheet. The difference between this embodiment and the fifth one isthat the weight ratio of water-based polyethylene wax to starch is 1:8.And the mixture is coated in an amount of 3 g/m² to the surface of papersheet. After that, the paper is post-dried and wound on a reel to getfinal product.

The surface repellency of transfer paper obtained by the presentdisclosure is tested by KIT standard (TAPPI 559 cm02) and the KIT gradescale is 1-12.

The present disclosure does not need coater. Therefore, it is able tofinish all the papermaking processes in the paper machine. Moreover, thecoating color need not be applied in the present disclosure, whichsolves paper-curling issue.

It is to be understood, however, that even though numerouscharacteristics and advantages of preferred and exemplary embodimentshave been set out in the foregoing description, together with details ofthe structures and functions of the embodiments, the disclosure isillustrative only; and that changes may be made in detail within theprinciples of present disclosure.

What is claimed is:
 1. A method for manufacturing transfer paper, comprising steps of pulp preparation, dissolution, refining, filtering, blend, dilution, pump, forming paper sheet, press, pre-drying, surface sizing, and after-drying, wherein surfactant is added after refining and before the paper sheet is formed.
 2. The method according to claim 1, wherein the surfactant comprises aqueous wax emulsion or fluorochemical.
 3. The method according to claim 2, wherein the aqueous wax emulsion comprises paraffin wax emulsion.
 4. The method according to claim 2, wherein the aqueous wax emulsion comprises water-based polyethylene wax.
 5. The method according to claim 2, wherein the fluorochemical comprises C3 or C6 or C8 organic fluorine oil repellent
 6. The method according to claim 2, wherein the fluorochemical comprises fluorine silicide.
 7. The method according to claim 1, wherein the surfactant is applied in an amount of 1-30 kilogram per ton of paper.
 8. A method for manufacturing transfer paper, comprising steps of pulp preparation, dissolution, refining, filtering, blend, dilution, pump, forming paper sheet, press, pre-drying, surface sizing, and after-drying, wherein surfactant is applied at the step of surface sizing.
 9. The method according to claim 8, wherein the surfactant comprises aqueous wax emulsion or fluorochemical.
 10. The method according to claim 9, wherein the aqueous wax emulsion comprises paraffin wax emulsion
 11. The method according to claim 9, wherein the aqueous wax emulsion comprises water-based polyethylene wax.
 12. The method according to claim 9, wherein the fluorochemical comprises C3 or C6 or C8 organic fluorine oil repellent
 13. The method according to claim 9, wherein the fluorochemical comprises fluorine silicide.
 14. The method according to claim 8, wherein the surfactant is applied in an amount of 1-30 kilogram per ton of paper.
 15. The method according to claim 8, wherein the surfactant is applied individually to the surface of paper sheet.
 16. The method according to claim 8, wherein the surfactant is applied with a mixture of sizing agents to the surface of paper sheet.
 17. The method according to claim 16, wherein the weight ratio of surfactant to sizing agents is from 1:5 to 1:10.
 18. The method according to claim 8, wherein the surfactant is applied in a paper machine. 